Mavic Open Pro & Open Pro CD



[email protected] wrote:
> Tom Ace wrote:
>
>>>> Are the 1980s rims you have in mind clincher or tubular rims?
>>>> 265g was about the weight of a Fiamme yellow label tubular rim.

>
>>>> Someone please correct me if I'm wrong, but I thought many tubular
>>>> rims of that era were not extruded but rather formed from sheet.
>>>> I have noticed a seam running all the way around the rim (in the
>>>> middle of the surface the tire glues to) on Mavic tubular rims
>>>> from the 70s and 80s.

>
>>> AFAIK Mavic, Fiamme, Super Champ, Weinmann, etc were all extruded
>>> and pinned at the seam opposite the valve with a shaped insert.

>
>> I put a pic of a mid-1980s Mavic GP4 tubular rim on the web at:

>
> http://minortriad.com/gp4.jpg
>
>> The seam I'm referring to is a small ridge on the top surface, and
>> there's a more pronounced blob on the underside of the same section
>> (visible through the valve hole).

>
>> If it's not a seam, what is it? I haven't seen anything like it on
>> the (extruded) clincher rims I've had.

>
> From what I have seen, those are artifacts produced by a floating core
> extrusion die and constitute a full depth weld in a neutral plane.


you absolute bullshitter! "a full depth weld in a neutral plane" of an
extrusion??? jobst, that is the most outstanding piece of made-up,
suppositional, pathetic attempt at trying to sound relevant, **** that
i've ever seen from you. and you've uttered some real peaches in the
past. absolutely outrageous.
 
Tom Ace wrote:
> On Jun 19, 1:13 pm, A Muzi <[email protected]> wrote:
>
>> Tom Ace wrote:
>>> Are the 1980s rims you have in mind clincher or tubular rims?
>>> 265g was about the weight of a Fiamme yellow label tubular rim.
>>> Someone please correct me if I'm wrong, but I thought many
>>> tubular rims of that era were not extruded but rather formed
>>> from sheet. I have noticed a seam running all the way around
>>> the rim (in the middle of the surface the tire glues to) on
>>> Mavic tubular rims from the 70s and 80s.

>> AFAIK Mavic, Fiamme, SuperChamp Weinmann etc were all extruded and
>> pinned at the seam opposite the valve with a shaped insert inside.

>
> I put a pic of a mid-1980s Mavic GP4 tubular rim on the web at
> http://minortriad.com/gp4.jpg
>
> The seam I'm referring to is a small ridge on the top surface,
> and there's a more pronounced blob on the underside of the
> same section (visible through the valve hole).
>
> If it's not a seam, what is it? I haven't seen anything like
> it on the (extruded) clincher rims I've had.
>


it's a telltale. all mavic rims have them. if there's a problem with
the extrusion, the telltale will disappear because it's a "fine" surface
feature indicating insufficient material flow.

and all rims are extruded. no "full depth weld in a neutral plane"!!!
 
On 2008-06-18 15:10:40 +0200, jim beam <[email protected]> said:

> other than that, if you're seeking wet weather wear resistance, skip
> ahead to the ceramic rim - the cd does increase wear resistance, but
> not hugely, and it does wear off. the ceramics are virtually wear
> proof.


I've got the Ceramice version and i adore them. braking in the wet (we
got a lot of that in denmark) with both campy and green swissstop pads
is exelent and they look like new though having ridden almost two years
(aslo durring winter time).

While they are great in wet weather they are even better when decenting
Galibier with 80km/t or the tricky turns down col du Mollard. Besides
braking performance it's very comforting to know that you don't have to
fear a blown tire due to hot rims

--
mvh. Morten Reippuert Knudsen

"Besides, if you can't get a decent kernal panic
or two in a month, what's the point of living?"
 
Tom Ace wrote:

>>> Are the 1980s rims you have in mind clincher or tubular rims?
>>> 265g was about the weight of a Fiamme yellow label tubular rim.


>>> Someone please correct me if I'm wrong, but I thought many tubular
>>> rims of that era were not extruded but rather formed from sheet.
>>> I have noticed a seam running all the way around the rim (in the
>>> middle of the surface the tire glues to) on Mavic tubular rims
>>> from the 70s and 80s.


>> AFAIK Mavic, Fiamme, Super Champion, Weinmann etc were all extruded
>> and pinned at the seam opposite the valve with a shaped insert
>> inside.


> I put a pic of a mid-1980s Mavic GP4 tubular rim on the web at


http://minortriad.com/gp4.jpg

> The seam I'm referring to is a small ridge on the top surface, and
> there's a more pronounced blob on the underside of the same section
> (visible through the valve hole).


> If it's not a seam, what is it? I haven't seen anything like it on
> the (extruded) clincher rims I've had.


A floating core in an extrusion is roughly like a jet engine pod on an
air liner, hanging in the extrusion die where the slender arm supports
the core to remain precisely located and causes a split in the shape
that closes after passing. That closure is essentially a full depth
"weld" leaving a bit of flash or a negative (groove) at that place in
the extrusion.

Jobst Brandt
 
Morten Reippuert Knudsen wrote:

>> other than that, if you're seeking wet weather wear resistance,
>> skip ahead to the ceramic rim - the cd does increase wear
>> resistance, but not hugely, and it does wear off. the ceramics are
>> virtually wear proof.


> I've got the Ceramice version and i adore them. braking in the wet
> (we got a lot of that in denmark) with both campy and green
> swissstop pads is exelent and they look like new though having
> ridden almost two years (aslo durring winter time).


> While they are great in wet weather they are even better when
> decenting Galibier with 80km/t or the tricky turns down col du
> Mollard. Besides braking performance it's very comforting to know
> that you don't have to fear a blown tire due to hot rims


Where does the braking energy go if it isn't heat? I don't understand
what you think is occurring when braking while descending. I assume
they are aluminum rims with ceramic coating. Heat generated by brakes
is the same regardless of rim or brake pad. It is the kinetic energy
of rider and bicycle.

Who makes thse rims and what is the model name?

> "Besides, if you can't get a decent kernal panic or two in a month,
> what's the point of living?"


What is a "decent kernal panic"?

Jobst Brandt
 
On Jun 20, 11:48 am, [email protected] wrote:
> Morten Reippuert Knudsen wrote:
> >> other than that, if you're seeking wet weather wear resistance,
> >> skip ahead to the ceramic rim - the cd does increase wear
> >> resistance, but not hugely, and it does wear off.  the ceramics are
> >> virtually wear proof.

> > I've got the Ceramice version and i adore them. braking in the wet
> > (we got a lot of that in denmark) with both campy and green
> > swissstop pads is exelent and they look like new though having
> > ridden almost two years (aslo durring winter time).
> > While they are great in wet weather they are even better when
> > decenting Galibier with 80km/t or the tricky turns down col du
> > Mollard.  Besides braking performance it's very comforting to know
> > that you don't have to fear a blown tire due to hot rims

>
> Where does the braking energy go if it isn't heat?  I don't understand
> what you think is occurring when braking while descending.  I assume
> they are aluminum rims with ceramic coating.  Heat generated by brakes
> is the same regardless of rim or brake pad.  It is the kinetic energy
> of rider and bicycle.
>
> Who makes thse rims and what is the model name?
>
> > "Besides, if you can't get a decent kernal panic or two in a month,
> > what's the point of living?"

>
> What is a "decent kernal panic"?
>
> Jobst Brandt


The ceramic line is basically the same as a CD (anodized, welded and
turned smooth at the joint) rim with ceramic bonded to the braking
surface.
I use them both on my winter and loaded touring bikes, with the same
results as this poster talked about. No real heat up, no fading,
etc. They brake almost the same in the wet as the dry, which is
impressive.
I've used these for >10 years now, with one set pulling through at the
eylets, and that was a set of touring wheels that went thousands of
loaded touring miles and many years.
It is interesting to speculate what happens to the heat with these
rims, but you can definitely touch them (even on our tandem) after a
long descent and they're just warm to the touch, not hot at all.
They're well worth their cost (roughly double a regular rim) both in
terms of being able to stop, consistently, and in terms of sidewall
wear. I usually go through a pair when I've hit too many holes riding
at night or similar...

-pete
 
Dan Overman wrote:

>>> "Besides, if you can't get a decent kernal panic or two in a month,
>>> what's the point of living?"


>> What is a "decent kernal panic"?


http://en.wikipedia.org/wiki/Kernel_Panic (?)

I don't see the connection between computer code and bicycle brakes
and life in general. The association is cryptic jargon to me.

Jobst Brandt
 
<[email protected]> wrote in message
news:0a6b7f0d-4cfa-4747-924c-f3fd525caaa6@r37g2000prm.googlegroups.com...

Thanks for that information about the ceramic rims Peter.
 
Peter Grey wrote:

>>>> other than that, if you're seeking wet weather wear resistance,
>>>> skip ahead to the ceramic rim - the cd does increase wear
>>>> resistance, but not hugely, and it does wear off.  the ceramics
>>>> are virtually wear proof.


>>> I've got the Ceramic version and i adore them. braking in the
>>> wet (we got a lot of that in Denmark) with both campy and green
>>> swissstop pads is excellent and they look like new though having
>>> ridden almost two years (also during winter time). While they
>>> are great in wet weather they are even better when descending
>>> Galibier with 80km/t or the tricky turns down col du Mollard.
>>>  Besides braking performance it's very comforting to know that you
>>> don't have to fear a blown tire due to hot rims


>> Where does the braking energy go if it isn't heat?  I don't
>> understand what you think is occurring when braking while
>> descending. I assume they are aluminum rims with ceramic coating.
>>  Heat generated by brakes is the same regardless of rim or brake
>> pad.  It is the kinetic energy of rider and bicycle.


>> Who makes these rims and what is the model name?


> The ceramic line is basically the same as a CD (anodized, welded and
> turned smooth at the joint) rim with ceramic bonded to the braking
> surface.


> I use them both on my winter and loaded touring bikes, with the same
> results as this poster talked about. No real heat up, no fading,
> etc. They brake almost the same in the wet as the dry, which is
> impressive.


Yes...? so where does the heat go and what sort of brake pads do they
require? Do these pads work on aluminum as well? I keep getting the
feeling that this is all secret and that non-members don't get any
details.

> I've used these for >10 years now, with one set pulling through at
> the eyelets, and that was a set of touring wheels that went
> thousands of loaded touring miles and many years.


My touring wheels go about 10,000 miles before the braking surface
wears down to 0.5mm and require a new rim. I also have rims that are
30 years old that are fine, but then I haven't ridden them in more
than 20 years. Years don't tell me much about rim wear.

> It is interesting to speculate what happens to the heat with these
> rims, but you can definitely touch them (even on our tandem) after a
> long descent and they're just warm to the touch, not hot at all.
> They're well worth their cost (roughly double a regular rim) both in
> terms of being able to stop, consistently, and in terms of sidewall
> wear. I usually go through a pair when I've hit too many holes
> riding at night or similar...


The heat did not go into the pad, they being insulators and have no
volume or surface f significance. That your rims are cool to the
touch must be because you touch them on the ceramic surface, an
insulator. You should feel if the base metal of the rim is hot,
possibly between spokes. Not knowing how these super rims look, what
the brand name and model is, I can make little of what is being said
here.

Jobst Brandt
 
Peter Grey wrote:

>> Who makes these rims and what is the model name?


> The ceramic line is basically the same as a CD (anodized, welded and
> turned smooth at the joint) rim with ceramic bonded to the braking
> surface.


So these are just Mavic Open Pro CD rims:

http://tinyurl.com/54lrlu
http://tinyurl.com/4f5kdj

* Maxtal with SUP welding reduces weight and vibrations while adding
strength

* Eyeleted design enhances strength around the spoke area and further
lightens the rim profile

* Ceramic 2 coating provides the incredible stopping power you need
when you're going fast

At $100 (Specialized) per rim you probably believe these claims. As
you say, the "enhances strength around the spoke area" caused spoke
pull-out while wet and dry braking is improved. That "welding reduces
weight and vibrations" also requires faith. My ancient Mavic MA-2
rims are dead steady at over 60mph on steep descents or I wouldn't let
the bicycle reach such speeds.

Jobst Brandt
 
In article
<0a6b7f0d-4cfa-4747-924c-f3fd525caaa6@r37g2000prm.googlegroups.com>,
[email protected] wrote:

> On Jun 20, 11:48 am, [email protected] wrote:
> > Morten Reippuert Knudsen wrote:
> > >> other than that, if you're seeking wet weather wear resistance,
> > >> skip ahead to the ceramic rim - the cd does increase wear
> > >> resistance, but not hugely, and it does wear off.  the ceramics are
> > >> virtually wear proof.
> > > I've got the Ceramice version and i adore them. braking in the wet
> > > (we got a lot of that in denmark) with both campy and green
> > > swissstop pads is exelent and they look like new though having
> > > ridden almost two years (aslo durring winter time).
> > > While they are great in wet weather they are even better when
> > > decenting Galibier with 80km/t or the tricky turns down col du
> > > Mollard.  Besides braking performance it's very comforting to know
> > > that you don't have to fear a blown tire due to hot rims

> >
> > Where does the braking energy go if it isn't heat?  I don't understand
> > what you think is occurring when braking while descending.  I assume
> > they are aluminum rims with ceramic coating.  Heat generated by brakes
> > is the same regardless of rim or brake pad.  It is the kinetic energy
> > of rider and bicycle.
> >
> > Who makes thse rims and what is the model name?
> >
> > > "Besides, if you can't get a decent kernal panic or two in a month,
> > > what's the point of living?"

> >
> > What is a "decent kernal panic"?

>
> The ceramic line is basically the same as a CD (anodized, welded and
> turned smooth at the joint) rim with ceramic bonded to the braking
> surface.
> I use them both on my winter and loaded touring bikes, with the same
> results as this poster talked about. No real heat up, no fading,
> etc. They brake almost the same in the wet as the dry, which is
> impressive.
> I've used these for >10 years now, with one set pulling through at the
> eylets, and that was a set of touring wheels that went thousands of
> loaded touring miles and many years.
> It is interesting to speculate what happens to the heat with these
> rims, but you can definitely touch them (even on our tandem) after a
> long descent and they're just warm to the touch, not hot at all.
> They're well worth their cost (roughly double a regular rim) both in
> terms of being able to stop, consistently, and in terms of sidewall
> wear. I usually go through a pair when I've hit too many holes riding
> at night or similar...


Some places the heat can go.

Ablation of the ceramic
Ablation of the brake pad
Surface of the ceramic gets very hot at the pad contact patch,
then dumps the heat into the wind stream.

--
Michael Press
 
In article <[email protected]>,
[email protected] wrote:

> Morten Reippuert Knudsen wrote:
>
> >> other than that, if you're seeking wet weather wear resistance,
> >> skip ahead to the ceramic rim - the cd does increase wear
> >> resistance, but not hugely, and it does wear off. the ceramics are
> >> virtually wear proof.

>
> > I've got the Ceramice version and i adore them. braking in the wet
> > (we got a lot of that in denmark) with both campy and green
> > swissstop pads is exelent and they look like new though having
> > ridden almost two years (aslo durring winter time).

>
> > While they are great in wet weather they are even better when
> > decenting Galibier with 80km/t or the tricky turns down col du
> > Mollard. Besides braking performance it's very comforting to know
> > that you don't have to fear a blown tire due to hot rims

>
> Where does the braking energy go if it isn't heat? I don't understand
> what you think is occurring when braking while descending. I assume
> they are aluminum rims with ceramic coating. Heat generated by brakes
> is the same regardless of rim or brake pad. It is the kinetic energy
> of rider and bicycle.
>
> Who makes thse rims and what is the model name?
>
> > "Besides, if you can't get a decent kernal panic or two in a month,
> > what's the point of living?"

>
> What is a "decent kernal panic"?


Failure of an operating at a fundamental level (the kernel.)
When I did QA work the goal was kernel panics.

--
Michael Press
 
[email protected] wrote:
> Tom Ace wrote:
>
>>>> Are the 1980s rims you have in mind clincher or tubular rims?
>>>> 265g was about the weight of a Fiamme yellow label tubular rim.

>
>>>> Someone please correct me if I'm wrong, but I thought many tubular
>>>> rims of that era were not extruded but rather formed from sheet.
>>>> I have noticed a seam running all the way around the rim (in the
>>>> middle of the surface the tire glues to) on Mavic tubular rims
>>>> from the 70s and 80s.

>
>>> AFAIK Mavic, Fiamme, Super Champion, Weinmann etc were all extruded
>>> and pinned at the seam opposite the valve with a shaped insert
>>> inside.

>
>> I put a pic of a mid-1980s Mavic GP4 tubular rim on the web at

>
> http://minortriad.com/gp4.jpg
>
>> The seam I'm referring to is a small ridge on the top surface, and
>> there's a more pronounced blob on the underside of the same section
>> (visible through the valve hole).

>
>> If it's not a seam, what is it? I haven't seen anything like it on
>> the (extruded) clincher rims I've had.

>
> A floating core in an extrusion is roughly like a jet engine pod on an
> air liner, hanging in the extrusion die where the slender arm supports
> the core to remain precisely located and causes a split in the shape
> that closes after passing.


1. whether or not the extrusion plug floats is utterly irrelevant. but
you'd not have said it if you knew what you were talking about.

2. the "closes after passing" is true for the whole extrusion - there's
no one part that is any seam. but you'd not have said it if you knew
what you're talking about.

> That closure is essentially a full depth
> "weld" leaving a bit of flash or a negative (groove) at that place in
> the extrusion.


see above. bullshitter.
 
[email protected] wrote:
> Peter Grey wrote:
>
>>> Who makes these rims and what is the model name?

>
>> The ceramic line is basically the same as a CD (anodized, welded and
>> turned smooth at the joint) rim with ceramic bonded to the braking
>> surface.

>
> So these are just Mavic Open Pro CD rims:
>
> http://tinyurl.com/54lrlu
> http://tinyurl.com/4f5kdj
>
> * Maxtal with SUP welding reduces weight and vibrations while adding
> strength
>
> * Eyeleted design enhances strength around the spoke area and further
> lightens the rim profile
>
> * Ceramic 2 coating provides the incredible stopping power you need
> when you're going fast
>
> At $100 (Specialized) per rim you probably believe these claims. As
> you say, the "enhances strength around the spoke area" caused spoke
> pull-out while wet and dry braking is improved. That "welding reduces
> weight and vibrations" also requires faith. My ancient Mavic MA-2
> rims are dead steady at over 60mph on steep descents or I wouldn't let
> the bicycle reach such speeds.
>


jobst, where do you get off? criticizing, from a position of ignorance,
something you've never used just doesn't cut it. because maybe, just
maybe, THERE'S SOMETHING YOU DON'T KNOW AND YOUR CRITICISM IS UNFOUNDED
********.
 
[email protected] wrote:
> Dan Overman wrote:
>
>>>> "Besides, if you can't get a decent kernal panic or two in a month,
>>>> what's the point of living?"

>
>>> What is a "decent kernal panic"?

>
> http://en.wikipedia.org/wiki/Kernel_Panic (?)
>
> I don't see the connection between computer code and bicycle brakes
> and life in general. The association is cryptic jargon to me.
>


i've yet to see any association between "jobst brandt" and engineering
in general.
 
Morten Reippuert Knudsen wrote:

>
> I've got the Ceramice version and i adore them. braking in the wet (we
> got a lot of that in denmark) with both campy and green swissstop pads
> is exelent and they look like new though having ridden almost two years
> (aslo durring winter time).
>


A short digression
Morten, how do the green swisstop pads wear compared to campy on your
rims? I have the same rims (and yes - they do enhance braking) and I
find that my campy pads wear pretty fast on the ceramic rims.

- jakob
 
On Jun 20, 2:03 pm, [email protected] wrote:
> Peter Grey wrote:
> >>>> other than that, if you're seeking wet weather wear resistance,
> >>>> skip ahead to the ceramic rim - the cd does increase wear
> >>>> resistance, but not hugely, and it does wear off.  the ceramics
> >>>> are virtually wear proof.
> >>> I've got the Ceramic version and i adore them.  braking in the
> >>> wet (we got a lot of that in Denmark) with both campy and green
> >>> swissstop pads is excellent and they look like new though having
> >>> ridden almost two years (also during winter time).  While they
> >>> are great in wet weather they are even better when descending
> >>> Galibier with 80km/t or the tricky turns down col du Mollard.
> >>>  Besides braking performance it's very comforting to know that you
> >>> don't have to fear a blown tire due to hot rims
> >> Where does the braking energy go if it isn't heat?  I don't
> >> understand what you think is occurring when braking while
> >> descending.  I assume they are aluminum rims with ceramic coating.
> >>  Heat generated by brakes is the same regardless of rim or brake
> >> pad.  It is the kinetic energy of rider and bicycle.
> >> Who makes these rims and what is the model name?

> > The ceramic line is basically the same as a CD (anodized, welded and
> > turned smooth at the joint) rim with ceramic bonded to the braking
> > surface.
> > I use them both on my winter and loaded touring bikes, with the same
> > results as this poster talked about.  No real heat up, no fading,
> > etc.  They brake almost the same in the wet as the dry, which is
> > impressive.

>
> Yes...? so where does the heat go and what sort of brake pads do they
> require?  Do these pads work on aluminum as well?  I keep getting the
> feeling that this is all secret and that non-members don't get any
> details.
>
> > I've used these for >10 years now, with one set pulling through at
> > the eyelets, and that was a set of touring wheels that went
> > thousands of loaded touring miles and many years.

>
> My touring wheels go about 10,000 miles before the braking surface
> wears down to 0.5mm and require a new rim.  I also have rims that are
> 30 years old that are fine, but then I haven't ridden them in more
> than 20 years.  Years don't tell me much about rim wear.
>
> > It is interesting to speculate what happens to the heat with these
> > rims, but you can definitely touch them (even on our tandem) after a
> > long descent and they're just warm to the touch, not hot at all.
> > They're well worth their cost (roughly double a regular rim) both in
> > terms of being able to stop, consistently, and in terms of sidewall
> > wear.  I usually go through a pair when I've hit too many holes
> > riding at night or similar...

>
> The heat did not go into the pad, they being insulators and have no
> volume or surface f significance.  That your rims are cool to the
> touch must be because you touch them on the ceramic surface, an
> insulator.  You should feel if the base metal of the rim is hot,
> possibly between spokes.  Not knowing how these super rims look, what
> the brand name and model is, I can make little of what is being said
> here.
>
> Jobst Brandt- Hide quoted text -
>
> - Show quoted text -

I typically get 2-3K/year/bike.
My tourer gets more/less some years, depending on length of tour that
year. Less lately since we're towing a toddler on tour, days are
shorter.
I agree, years don't mean much, but miles do. I typically beat up a
rim prior to going through the sidewalls. This is on my winter bike
here as well, in the Seattle area, where winter road-grit is the norm,
not the exception.

I've tried feeling outside the ceramic, and again, they're not really
that hot. I've descended on a tandem with non-ceramics, and on
touring bikes, and I know how hot the rims get in these circumstances.

Nothing that secret about them, Mavic mapes the Open series with
ceramic, as do a couple of other manuf. periodically. You just don't
see 'em at your typical LBS, sinc they're roughly double the cost up-
front. I think people have trouble seeing the value.
The first time you come to a quick stop on a blazing-fast descent in a
big rainstorm (at least as fast as tire-friction will let you), the
value speaks for itself, IMHO.

-pete
 
[email protected] wrote:

>>> I use them both on my winter and loaded touring bikes, with the
>>> same results as this poster talked about.  No real heat up, no
>>> fading, etc.  They brake almost the same in the wet as the dry,
>>> which is impressive.


>> Yes...? so where does the heat go and what sort of brake pads do
>> they require?  Do these pads work on aluminum as well?  I keep
>> getting the feeling that this is all secret and that non-members
>> don't get any details.


>>> I've used these for >10 years now, with one set pulling through at
>>> the eyelets, and that was a set of touring wheels that went
>>> thousands of loaded touring miles and many years.


>> My touring wheels go about 10,000 miles before the braking surface
>> wears down to 0.5mm and require a new rim.  I also have rims that
>> are 30 years old that are fine, but then I haven't ridden them in
>> more than 20 years.  Years don't tell me much about rim wear.


>>> It is interesting to speculate what happens to the heat with these
>>> rims, but you can definitely touch them (even on our tandem) after
>>> a long descent and they're just warm to the touch, not hot at all.
>>> They're well worth their cost (roughly double a regular rim) both
>>> in terms of being able to stop, consistently, and in terms of
>>> sidewall wear.  I usually go through a pair when I've hit too many
>>> holes riding at night or similar...


>> The heat did not go into the pad, they being insulators and have no
>> volume or surface f significance.  That your rims are cool to the
>> touch must be because you touch them on the ceramic surface, an
>> insulator.  You should feel if the base metal of the rim is hot,
>> possibly between spokes.  Not knowing how these super rims look,
>> what the brand name and model is, I can make little of what is
>> being said here.


> I typically get 2-3K/year/bike. My tourer gets more/less some
> years, depending on length of tour that year. Less lately since
> we're towing a toddler on tour, days are shorter. I agree, years
> don't mean much, but miles do. I typically beat up a rim prior to
> going through the sidewalls. This is on my winter bike here as
> well, in the Seattle area, where winter road-grit is the norm, not
> the exception.


> I've tried feeling outside the ceramic, and again, they're not
> really that hot. I've descended on a tandem with non-ceramics, and
> on touring bikes, and I know how hot the rims get in these
> circumstances.


I think that is an unclear temperature measure because ceramic is an
insulator and may not reveal the temperature of the aluminum rim as
readily as a bare aluminum rim.

> Nothing that secret about them, Mavic makes the Open series with
> ceramic, as do a couple of others periodically. You just don't see
> 'em at your typical LBS, since they're roughly double the cost up-
> front. I think people have trouble seeing the value. The first
> time you come to a quick stop on a blazing-fast descent in a big
> rainstorm (at least as fast as tire-friction will let you), the
> value speaks for itself, IMHO.


I read such endorsements here and try to explain why this should
happen. As I explained, braking does not become effective until the
rim is mostly dry. A ceramic rim can get a hot surface more quickly
than a bare aluminum rim. Therefore, it can begin braking sooner and
with less effort than bare aluminum.

I'm not sure this is what occurs, but it is an explanation. I come to
this because I rode wooden rims that braked well when initially wet.
They also develop a hot surface because they don't conduct heat, but
to make up for that, I found they ate up brake blocks by melting them.

I don't think you can have it both ways. That's why I ask where the
heat is supposed to go and how does one get rid of it. No one has
approached that matter and we seem to leave it a mystery. I am
skeptical because in the early days of hard anodized rims (effectively
ceramic coated) brakes worked poorly because the conventional pads
melted.

We need something more than "I use them and like them" to assess how
good they are. I've descended many miles in rain with slightly
reduced performance on bare aluminum rims, and complete brake failure
when snow piled up on the inner radius of Fiamme road rims and watered
the braking surface until all snow had melted and run off.

Jobst
 
[email protected] wrote:
> [email protected] wrote:
>
>>>> I use them both on my winter and loaded touring bikes, with the
>>>> same results as this poster talked about. No real heat up, no
>>>> fading, etc. They brake almost the same in the wet as the dry,
>>>> which is impressive.

>
>>> Yes...? so where does the heat go and what sort of brake pads do
>>> they require? Do these pads work on aluminum as well? I keep
>>> getting the feeling that this is all secret and that non-members
>>> don't get any details.

>
>>>> I've used these for >10 years now, with one set pulling through at
>>>> the eyelets, and that was a set of touring wheels that went
>>>> thousands of loaded touring miles and many years.

>
>>> My touring wheels go about 10,000 miles before the braking surface
>>> wears down to 0.5mm and require a new rim. I also have rims that
>>> are 30 years old that are fine, but then I haven't ridden them in
>>> more than 20 years. Years don't tell me much about rim wear.

>
>>>> It is interesting to speculate what happens to the heat with these
>>>> rims, but you can definitely touch them (even on our tandem) after
>>>> a long descent and they're just warm to the touch, not hot at all.
>>>> They're well worth their cost (roughly double a regular rim) both
>>>> in terms of being able to stop, consistently, and in terms of
>>>> sidewall wear. I usually go through a pair when I've hit too many
>>>> holes riding at night or similar...

>
>>> The heat did not go into the pad, they being insulators and have no
>>> volume or surface f significance. That your rims are cool to the
>>> touch must be because you touch them on the ceramic surface, an
>>> insulator. You should feel if the base metal of the rim is hot,
>>> possibly between spokes. Not knowing how these super rims look,
>>> what the brand name and model is, I can make little of what is
>>> being said here.

>
>> I typically get 2-3K/year/bike. My tourer gets more/less some
>> years, depending on length of tour that year. Less lately since
>> we're towing a toddler on tour, days are shorter. I agree, years
>> don't mean much, but miles do. I typically beat up a rim prior to
>> going through the sidewalls. This is on my winter bike here as
>> well, in the Seattle area, where winter road-grit is the norm, not
>> the exception.

>
>> I've tried feeling outside the ceramic, and again, they're not
>> really that hot. I've descended on a tandem with non-ceramics, and
>> on touring bikes, and I know how hot the rims get in these
>> circumstances.

>
> I think that is an unclear temperature measure because ceramic is an
> insulator and may not reveal the temperature of the aluminum rim as
> readily as a bare aluminum rim.


electrical insulator does not mean thermal insulator. take diamond for
example. alumina is not too shabby a thermal conductor either, and
guess what, the ceramic used here is substantially alumina. whodathunkit.


>
>> Nothing that secret about them, Mavic makes the Open series with
>> ceramic, as do a couple of others periodically. You just don't see
>> 'em at your typical LBS, since they're roughly double the cost up-
>> front. I think people have trouble seeing the value. The first
>> time you come to a quick stop on a blazing-fast descent in a big
>> rainstorm (at least as fast as tire-friction will let you), the
>> value speaks for itself, IMHO.

>
> I read such endorsements here and try to explain why this should
> happen. As I explained, braking does not become effective until the
> rim is mostly dry.


than you've not used one of these rims then jobst! why don't you ever
restrict your blathering to subjects where you actually /know/ what's
happening rather than merely supposing?


> A ceramic rim can get a hot surface more quickly
> than a bare aluminum rim. Therefore, it can begin braking sooner and
> with less effort than bare aluminum.


aren't you one of the people that told us braking depended on coolness,
not hotness?


>
> I'm not sure this is what occurs, but it is an explanation.


so why do you write in definitive terms? "braking does not become
effective" for example.



> I come to
> this because I rode wooden rims that braked well when initially wet.
> They also develop a hot surface because they don't conduct heat, but
> to make up for that, I found they ate up brake blocks by melting them.


and guess what, we have specialized brakes pad materials available for
ceramic rims! whodathunkit.


>
> I don't think you can have it both ways. That's why I ask where the
> heat is supposed to go and how does one get rid of it. No one has
> approached that matter and we seem to leave it a mystery. I am
> skeptical because in the early days of hard anodized rims (effectively
> ceramic coated) brakes worked poorly because the conventional pads
> melted.


why didn't mine?


>
> We need something more than "I use them and like them" to assess how
> good they are.


"we"??? /you/ actually buying some and bothering to use them might be a
place to start!!! how long have they been out now? 10 years? more?


> I've descended many miles in rain with slightly
> reduced performance on bare aluminum rims, and complete brake failure
> when snow piled up on the inner radius of Fiamme road rims and watered
> the braking surface until all snow had melted and run off.


[yawn].